package com.hw.utils;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;


/**
 *
 * 使用DES加密与解密,可对byte[],String类型进行加密与解密 密文可使用String,byte[]存储.
 *
 * 方法: void getKey(String strKey)从strKey的字条生成一个Key
 *
 * String getEncString(String strMing)对strMing进行加密,返回String密文 String
 * getDesString(String strMi)对strMin进行解密,返回String明文
 *
 * byte[] getEncCode(byte[] byteS)byte[]型的加密 byte[] getDesCode(byte[]
 * byteD)byte[]型的解密
 */

public class DESCrypt {
	private byte[] desKey;


	//解密数据
	public static String decrypt(String message,String key) throws Exception {

		byte[] bytesrc =convertHexString(message);
		Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
		IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));

		cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);

		byte[] retByte = cipher.doFinal(bytesrc);
		return new String(retByte);
	}

	public static byte[] encrypt(String message, String key)
			throws Exception {
		Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
		IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
		cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

		return cipher.doFinal(message.getBytes("UTF-8"));
	}

	public static byte[] convertHexString(String ss)
	{
		byte digest[] = new byte[ss.length() / 2];
		for(int i = 0; i < digest.length; i++)
		{
			String byteString = ss.substring(2 * i, 2 * i + 2);
			int byteValue = Integer.parseInt(byteString, 16);
			digest[i] = (byte)byteValue;
		}

		return digest;
	}


	public static void main(String[] args) throws Exception {
		String key = "ahhwxxjs";
		String value="12323";
		String jiami=java.net.URLEncoder.encode(value, "utf-8").toLowerCase();

		System.out.println("加密数据:"+jiami);
		String a=toHexString(encrypt(jiami, key)).toUpperCase();


		System.out.println("加密后的数据为:"+a);
		/*String b=java.net.URLDecoder.decode(decrypt(a,key), "utf-8") ;
		System.out.println("解密后的数据:"+b);*/

	}


	public static String toHexString(byte b[]) {
		StringBuffer hexString = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			String plainText = Integer.toHexString(0xff & b[i]);
			if (plainText.length() < 2)
				plainText = "0" + plainText;
			hexString.append(plainText);
		}

		return hexString.toString();
	}


}
